His devotion is to the word. His power is of seduction. He goes to seek out problems where they are. The impetus of inspiration is very much part of his style. Books reflect the breadth of his tastes very well. He stopped smoking to have the moral authority to combat tobacco addiction. He likes to prepare food recipes with a kind of scientific fervour. He keeps himself in excellent physical condition with various hours of gymnastics daily and frequent swimming. Invincible patience. Ironclad discipline. The force of his imagination stretches him to the unforeseen.

José Martí is his foremost author and he has had the talent to incorporate Martí's thinking into the sanguine torrent of a Marxist revolution. The essence of his own thinking could lie in the certainty that in undertaking mass work it is fundamental to be concerned about individuals.

That could explain his absolute confidence in direct contact. He has a language for each occasion and a distinct means of persuasion according to his interlocutors. He knows how to put himself at the level of each one, and possesses a vast and varied knowledge that allows him to move with facility in any media. One thing is definite: he is where he is, how he is and with whom he is.

Fidel Castro is there to win. His attitude in the face of defeat, even in the most minimal actions of everyday life, would seem to obey a private logic: he does not even admit it, and does not have a minute's peace until he succeeds in inverting the terms and converting it into victory.

His supreme aide is his memory and he uses it, to the point of abuse, to sustain speeches or private conversations with overwhelming reasoning and arithmetical operations of an incredible rapidity. He requires incessant information, well masticated and digested. He breakfasts with no less than 200 pages of news. Responses have to be exact, given that he is capable of discovering the most minimal contradiction in a casual phrase. He is a voracious reader. He is prepared to read any paper that comes into his hands at any hour.

He does not lose any occasion to inform himself. During the Angola war he described a battle in such detail at an official reception that it was hard work to convince a European diplomat that Fidel Castro had not participated in it.

His vision of Latin America in the future is the same as that of Bolívar and Martí, an integrated and autonomous community, capable of moving the destiny of the world. The country about which he knows the most after Cuba is the United States: of the nature of its people, their power structures, the secondary intentions of its governments. And this has helped him to handle the incessant torment of the blockade.

He has never refused to answer any question, however provocative it might be, nor has he ever lost his patience. In terms of those who are economical with the truth, in order not to give him any more concerns than those that he already has: he knows it. He said to one official who did so: "You are hiding truths from me, in order not to worry me, but when I finally discover them I will die from the impact of having to confront so many truths I have not been told." But gravest are the truths concealed to cover up deficiencies, because alongside the enormous achievements that sustain the revolution - the political, scientific, sporting, cultural achievements - there is a colossal bureaucratic incompetence, affecting daily life, and particularly domestic happiness.

When he talks with people in the street, his conversation regains the expressiveness and crude frankness of genuine affection. They call him: Fidel. They address him informally, they argue with him, they claim him. It is then that one discovers the unusual human being that the reflection of his own image does not let us see. This is the Fidel Castro that I believe I know. A man of austere habits and insatiable illusions, with an old-fashioned formal education of cautious words and subdued tones, and incapable of conceiving any idea that is not colossal.

I have heard him evoking things that he could have done in another way to gain time in life. On seeing him very overburdened with the weight of so many distant destinies, I asked him what it was that he most wished to do in this world, and he immediately answered me: "Stand on a corner."

· Gabriel García Márquez is a Nobel prize-winning novelist. This is an edited extract of an article from the Cuban newspaper Granma. Fidel Castro is 80 tomorrow